1906.] Growth and Activity of the Mammary Glands. 515 



B received the unboiled extract of 55 placenta-. It was killer! on November 2. 

 Mammary glands unchanged ; uterus slightly congested. 



IV. — Injection of Foetus with or "•ithout Placenta and Uterine Mucous Membrane. 



The first three experiments on this point were also fruitless so far as regards any 

 change in the mammary glands. In these cases the rabbits received from five to seven 

 injections of extract of foetus. The following experiments, therefore, were conducted 

 for a longer period of time, and a much larger number of injections were given, and 

 in these positive results were obtained. 



Experiment 9 — February 8, 1905. — A rabbit, eight months old, which had been in the 

 laboratory since it was a fortnight old — virgin — received, subcutaneousty, extracts made 

 by rubbing up foetuses and their placeuta; with sand, extracting with normal saline, 

 centrifuging, and filtering through a Berkefeld. The injections were made as follows : — 



February 8. — Half the extract of 7 fretuses at the 20th day. 

 „ 9.— „ „ 1 „ 20th „ 



10. — 4 foetuses at the 22nd day. 



„ 11.— 5 „ 14th ,. 



„ 13.— 4 „ 14th ., 



„ 14.— 3 „ 22nd ., 



„ 15.— 4 „ 20th „ 



„ 16.— Half the extract of 8 foetuses at the 20th day. 



„ 17— „ „ 8 „ 20th „ 



„ 18.— 6 fcetuses at the 19th day. 



„ 20.— 5 „ 14th „ 



„ 21. — Half extract of viscera of 6 fcetuses at the 25th day. 



„ 22.— „ „ 6 „ 25th „ 



,, 23. — Viscera of 7 fcetuses at the 20th day. 



„ 24.— „ 4 „ 24th „ 



The rabbit was killed on February 25. There was marked hypertrophy of the- 

 mammary glands, which were surrounded with a certain amount of fluid remaining from 

 the subcutaneous injections. The ovaries were large, the uterus congested, and the vulva 

 showed signs of heat. On microscopic examination there was found to be marked hyper- 

 trophy of ducts, which were branching and lined with many layers of cells. The mitotic- 

 figures were numerous. Specimens of the mammary glands from this rabbit were shown 

 at the meeting of the Physiological Society at University College in March, 1905. 



Experiment 10. February 27, 1905. — Intraperitoneal injection of press-juice of the- 

 viscera of foetuses, together with placenta; and uterine mucous membrane. 



A virgin rabbit received the following injections : — 



February 27. — 8 foetuses, etc., at 24th day. 



„ 28.— Half of 9 foetuses, etc., at 24th day-. 

 March 1.— „ 9 „ 24th „ 



„ 2. — 8 fcetuses, etc., at 25th day. 



3. -8 



4. -2 



